Hydrodynamic pressure finger seal1 is a kind of flexible noncontact dynamic sealing device with good application potential. It relies on the ultrathin dynamic pressure film effect produced by the rotation of finger boot and rotor to realize the design of noncontact and low leakage and is suitable for high-speed dynamic sealing parts. However, under the high-speed condition, there is a wall slip effect when the gas flows in the microchannel with a thickness of about 10 μm between the finger boot and rotor, which affects the stability of the dynamic pressure air film and also affects the change of the air film bearing capacity and the leakage rate of the finger seal. Therefore, based on the theory of microflow, the interstitial flow field model of finger seal under fluid dynamic pressure is established, and its slip effect under high speed is analyzed. The results show that the slip ratio of the sealing medium temperature of 500°C and 0.1 MPa conditions reached 27.28%. When considering the slip effect of the wall surface generated by the gas under shear driving, the gas film bearing capacity decreased and the leakage rate increased. When the pressure difference between the upper and lower reaches of the seal is 0.1 MPa, and the rotor line speed is 400 m/s, the gas film bearing capacity decreases by 17.39% after considering the slip effect of the wall surface, and the leakage rate increases by 14.06%. The results provide an important reference for the structural design and leakage control of hydrodynamic finger seal.

中文翻译：

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壁滑效应对动压手指密封性能的分析

流体动压手指密封1是一种具有良好应用潜力的柔性非接触动态密封装置。它依靠指套和转子旋转产生的超薄动压膜效应来实现非接触和低泄漏的设计，适用于高速动密封件。然而，高速条件下，有一个壁防滑效果时的气体中的微通道的厚度约10的流动 μ指套与转子之间的距离m，不仅影响动压气膜的稳定性，还影响气膜承载力的变化和指密封件的泄漏率。因此，基于微流理论，建立了流体动压作用下指状密封的间隙流场模型，并对其在高速下的滑移效应进行了分析。结果表明，在500℃密封介质温度和0.1MPa条件下的滑移率达到27.28％。考虑剪切驱动下气体产生的壁表面的滑移效应，气膜承载能力降低，泄漏率增加。当密封件的上部和下部之间的压力差为0.1 MPa，并且转子线速度为400 m / s时，气膜承载能力降低17。考虑壁面的滑移效应后为39％，泄漏率增加了14.06％。研究结果为流体动力手指密封的结构设计和泄漏控制提供了重要的参考。